//
// Copyright (c) 2019 muukii
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

public struct EntityIdentifier<Entity: EntityType> : Hashable, CustomStringConvertible, Sendable {

  public static func == (lhs: Self, rhs: Self) -> Bool {
    lhs.raw == rhs.raw
  }

  public func hash(into hasher: inout Hasher) {
    raw.hash(into: &hasher)
  }

  public let raw: Entity.EntityIDRawType

  public init(_ raw: consuming Entity.EntityIDRawType) {
    self.raw = raw
  }

  public var description: String {
    "<\(String(reflecting: Entity.self))>(\(raw))"
  }
}

/// A protocol describes object is an Entity.
public protocol EntityType: Identifiable, Equatable, Sendable {

  associatedtype EntityIDRawType: Hashable, Sendable

  var entityID: EntityID { get }

  typealias EntityID = EntityIdentifier<Self>
}

extension EntityType {
  public var id: EntityID {
    entityID
  }
}
